What's the difference between rhabdom and rhabdomere?
Rhabdom
Definition:
(n.) One of numerous minute rodlike structures formed of two or more cells situated behind the retinulae in the compound eyes of insects, etc. See Illust. under Ommatidium.
Example Sentences:
(1) On dark-adaptation of the 11-day adult eye, the rhabdomers move towards the cuticle.
(2) The rhabdom of the larval eye, if cut longitudinally, exhibits a "banded" structure over its entire length; in the adult the banded part is confined to the distal end, and the rhabdom is tiered.
(3) In all other ommatidia, the proximal parts of the rhabdoms show radially arranged microvilli, whereas the distal parts may reveal different patterns, frequently with microvilli in two directions or sometimes even in one direction.
(4) A calculation of the theoretical field size of individual retinula cells from measurments of refractive index and lens dimensions predicts that cells which participate in the central rhabdom will have acceptance angles near 3 degrees.
(5) All retinula cells run the entire length from the cone to the basal lamina, although two, called the proximal cells, only contribute to the lowest third of the rhabdom, and one of either cell 6 or cell 7 on our arbitrary numbering system forms its axon one third the way up the ommatidium.
(6) In the dark, a distinct gradient of activity was observed with radioactivity concentrated distally and declining toward the proximal end of the rhabdome.
(7) An admittance function was defined as the percentage of the rays reaching the rhabdom with respect to those entering the ommatidium.
(8) In spite of a one h exposure to light, rhabdom microvilli show no disintegration or disruption of membranes.
(9) The rhabdom of isolated small photoreceptors is surrounded by a calyx originating from the soma, so that it appears to be located internally.
(10) After 1-h illumination (225-320 lux), further reduction of rhabdom diameter was modest in control retinae but precipitate in those treated with OKA.
(11) Foot cells which lie immediately below the rhabdom also contain similar junctions and actin is tentatively identified in these cells.
(12) Three different fractions of visual cell fragments were prepared from the retina: the MV-fraction containing the rhabdomal microvilli, and the PVH- and PVL-fractions containing the photic vesicles located in the visual cell body.
(13) Sometimes seven and sometimes eight retinular cells closely appose the proximal tip of the cone and bear the microvilli of the rhabdom.
(14) Rhabdom sizes were not compromised by OKA, nor by either of the two protein kinase activators, SC-9 or PDA when each was deployed alone in darkness.
(15) A clear zone between dioptric structures and the rhabdom layer is absent.
(16) In Loricera and Agonum roots at the level of the proximal rhabdom are not continuous with the rootlets or short roots associated with the centrioles.
(17) In both cases, microvilli of the rhabdom were severely disrupted and the retinular cytoplasm contained numerous multivesicular bodies.
(18) Exposure to light seems to activate a transport mechanism that results in the redistribution of retinoid between the inner segments and rhabdomes and chromophore exchange among the photopigments.
(19) Quantification of the electron microscopic autoradiograms revealed that labeling of the cytoplasm was greater than the rhabdome at 2, 5, and 30 minutes and reached a peak at 12 hours.
(20) Extensive areas of gap junctions which occur between the rhabdoms and the membranes of large and small cells suggest that the cells may be electrically coupled to one another.
Rhabdomere
Definition:
(n.) One of the several parts composing a rhabdom.
Example Sentences:
(1) Rhabdomeres are substantially smaller and visual pigment is nearly eliminated when Drosophila are carotenoid-deprived from egg to adult.
(2) The deficit of transcript concentration correlated with the severity of developmental defect in rhabdomere formation along the cell.
(3) R7 and R8 have normal rhabdomeres, and in particular, they have normal coated vesicles and multivesicular bodies (MVB's), early steps in the degradation phase of normal rhabdomere maintenance.
(4) The immunoreactivity appears predominantly in the retinal and occellar rhabdomeres.
(5) Over the four developmental stages examined there is an increase in the number of microvilli forming the rhabdomeres and a 50% decrease in the mean cross-sectional area of individual microvilli.
(6) These data suggest that in rhabdomeric photoreceptors of invertebrates light-activation of rhodopsin is coupled to an enzyme cascade in a similar way as in the ciliary photoreceptors of vertebrates, although there may be differences, e.g.
(7) Carotenoid replaced flies show an increase in visual pigment possibly associated with a streaming of membrane into the rhabdomere.
(8) Freeze-fracture and etch views of the rhabdomeres also indicate that adjacent microvilli are separated by a 6-8-nm-wide extracellular space along most of their length.
(9) These findings suggest that the P-face particles in the microvillar membrane are associated with rhodopsin, that the receptor cells have a small amount of rhodopsin before rhabdomere formation, and that differentiation of the apical plasma membrane of the receptor cells into the functional photoreceptive membrane occurs in conjunction with its morphological differentiation into rhabdomeres.
(10) In the fully differentiated ommatidium only two types of junction remain, these are: desmosomes and rhabdomeric junctions.
(11) The results support the conclusion that the receptor potential originates in retinular cells within the membrane system of the rhabdomere.
(12) The amount of 3H-amino acids incorporated in rdgA rhabdomeres at 3 hr after the injection was about 50%, and that of 3H-sugar residues was about 20% of normal.
(13) Density of immunogold, specific to R1-6 (vs. R7), increases between days 1 and 3 of replacement as visual pigment and rhabdomeres recover.
(14) In the majority of ommatidia of the fly, the membrane of the central rhabdomere contains--besides the rhodopsin--a photostable pigment.
(15) In developing flies, faint immunoreactivity appears in the retinal rhabdomeres at about 70% of the time through pupal development and increases to its apparent adult maximal level about 1 day after eclosion.
(16) Thirteen per cent of the volume of the photoreceptor cells is taken up by the rhabdomeres.
(17) The modification of the latent period may depend upon the direction of current flow across some regions of the membrane system constituting the rhabdomere.
(18) It was found that after bright light exposure large numbers of little screening pigment granules (0.15-0.3 microns) were located between or close to rhabdomeral microvilli that were not at these sites in crayfish kept under natural light.
(19) Construction and analysis of a 3'-deletion mutant of ninaE indicates that translational readthrough accounts for the extra photoreceptor activity of the ninaE309 alleles and that truncated opsins are responsible for the improved rhabdomere structure.
(20) In the retinula, R7 has a large apical rhabdomere with microvilli aligned along the animal's horizon, and a basal axon.